Liquid discharge apparatus, drive waveform generator, and head drive method

Abstract

A liquid discharge apparatus includes a liquid discharge head configured to discharge a liquid, and a drive waveform generator configured to generate a drive waveform to be applied to the liquid discharge head, the drive waveform including a first discharge pulse to cause the liquid discharge head to discharge the liquid, a second discharge pulse after the first discharge pulse, the second discharge pulse to cause the liquid discharge head to discharge the liquid, and a pulse interval between the first discharge pulse and the second discharge pulse, the pulse interval being equal to a time period in which the liquid is discharged by the second discharge pulse in a damping state in which the second discharge pulse is damped by a meniscus vibration generated by the first discharge pulse.

What is claimed is: 
     
       1. A liquid discharge apparatus comprising:
 a liquid discharge head configured to discharge a liquid; and 
 a drive waveform generator configured to generate a drive waveform to be applied to the liquid discharge head, 
 the drive waveform including: 
 a plurality of discharge pulses consisting of a first discharge pulse to cause the liquid discharge head to discharge the liquid and a second discharge pulse after the first discharge pulse to cause the liquid discharge head to discharge the liquid, the first discharge pulse and the second discharge pulse are in a nonresonant state; 
 a pulse interval between the first discharge pulse and the second discharge pulse, the pulse interval is set to a time period in which the liquid is discharged by the second discharge pulse in the nonresonant state in which the second discharge pulse is nonresonant with a meniscus vibration generated by the first discharge pulse; and 
 a non-discharge pulse between the first discharge pulse and the second discharge pulse, wherein the non-discharge pulse generates another meniscus vibration that does not cause the liquid discharge head to discharge the liquid. 
 
     
     
       2. The liquid discharge apparatus according to  claim 1 ,
 wherein the drive waveform further includes another pulse interval between the non-discharge pulse and the second discharge pulse, said another pulse interval being equal to a time period in which the liquid is discharged by the second discharge pulse in a resonant state in which the second discharge pulse is resonant with said another meniscus vibration generated by the non-discharge pulse. 
 
     
     
       3. The liquid discharge apparatus according to  claim 1 ,
 wherein the drive waveform further includes another pulse interval between the first discharge pulse and the non-discharge pulse, said another pulse interval being equal to a time period in which said another meniscus vibration generated by the non-discharge pulse is damped by the meniscus vibration generated by the first discharge pulse. 
 
     
     
       4. The liquid discharge apparatus according to  claim 1 ,
 wherein the liquid discharge head includes; 
 a nozzle from which the liquid is discharged; and 
 a pressure chamber communicating with the nozzle, the pressure chamber accommodating the liquid to be discharged from the nozzle, and 
 the non-discharge pulse includes: 
 an expansion waveform element to expand the pressure chamber; 
 a holding waveform element to hold an expansion state of the pressure chamber expanded by the expansion waveform element; and 
 a contraction waveform element to contract the pressure chamber from a state held by the holding waveform element, and 
 the holding waveform element has a pulse width equal to a time period shorter than a cycle of said another meniscus vibration generated by the non-discharge pulse. 
 
     
     
       5. The liquid discharge apparatus according to  claim 1 ,
 wherein the liquid discharge head includes; 
 a nozzle from which the liquid is discharged; and 
 a pressure chamber communicating with the nozzle, the pressure chamber accommodating the liquid to be discharged from the nozzle, and 
 the non-discharge pulse includes: 
 an expansion waveform element to expand the pressure chamber; 
 a holding waveform element to hold an expansion state of the pressure chamber expanded by the expansion waveform element; and 
 a contraction waveform element to contract the pressure chamber from a state held by the holding waveform element, and 
 the first discharge pulse includes: 
 a first expansion waveform element to expand the pressure chamber; 
 a first holding waveform element to hold an expansion state of the pressure chamber expanded by the first expansion waveform element; and 
 a first contraction waveform element to contract the pressure chamber from a state held by the first holding waveform element, and 
 the second discharge pulse includes: 
 a second expansion waveform element to expand the pressure chamber; 
 a second holding waveform element to hold an expansion state of the pressure chamber expanded by the second expansion waveform element; and 
 a second contraction waveform element to contract the pressure chamber from a state held by the second holding waveform element, and 
 the non-discharge pulse has a voltage changing time being a sum of a changing time of the expansion waveform element and the contraction waveform element, 
 the first discharge pulse has a voltage changing time being a sum of a changing time of the first expansion waveform element and the first contraction waveform element, and 
 the second discharge pulse has a voltage changing time being a sum of a changing time of the second expansion waveform element and the second contraction waveform element, and 
 the voltage changing time of the non-discharge pulse is shorter than the voltage changing time of each of the first discharge pulse and the second discharge pulse. 
 
     
     
       6. The liquid discharge apparatus according to  claim 1 ,
 wherein the non-discharge pulse includes one or more non-discharge pulses. 
 
     
     
       7. The liquid discharge apparatus according to  claim 1 ,
 wherein the liquid discharge head includes: 
 a nozzle from which the liquid is discharged; and 
 a pressure chamber communicating with the nozzle, the pressure chamber accommodating the liquid to be discharged from the nozzle, and 
 the first discharge pulse includes: 
 a first expansion waveform element to expand the pressure chamber; 
 a first holding waveform element to hold an expansion state of the pressure chamber expanded by the first expansion waveform element; and 
 a first contraction waveform element to contract the pressure chamber from a state held by the first holding waveform element, and 
 the first holding waveform element has a pulse interval equal to a time period in which the liquid is discharged by the first contraction waveform element in a resonant state in which the first contraction waveform element is resonant with a meniscus vibration generated by the first expansion waveform element. 
 
     
     
       8. The liquid discharge apparatus according to  claim 1 ,
 wherein the liquid discharge head includes: 
 a nozzle from which the liquid is discharged; and 
 a pressure chamber communicating with the nozzle, the pressure chamber accommodating the liquid to be discharged from the nozzle, and 
 the second discharge pulse includes: 
 a second expansion waveform element to expand the pressure chamber; 
 a second holding waveform element to hold an expansion state of the pressure chamber expanded by the second expansion waveform element; and 
 a second contraction waveform element to contract the pressure chamber from a state held by the second holding waveform element, and 
 the second holding waveform element has a pulse interval equal to a time period in which the liquid is discharged by the second contraction waveform element in a resonant state in which the second contraction waveform element is resonant with a meniscus vibration generated by the second expansion waveform element. 
 
     
     
       9. The liquid discharge apparatus according to  claim 1 , wherein the pulse interval is set to a shortest time period in which the liquid is discharged by the second discharge pulse in the nonresonant state in which the second discharge pulse is nonresonant with the meniscus vibration generated by the first discharge pulse. 
     
     
       10. The liquid discharge apparatus according to  claim 1 , wherein the first discharge pulse and the second discharge pulse are the only discharge pulses of the plurality of discharge pulses. 
     
     
       11. The liquid discharge apparatus according to  claim 10 , wherein the second discharge pulse has a potential that is larger than a potential of the first discharge pulse, and the potential of the first discharge pulse is larger than a potential of the non-discharge pulse. 
     
     
       12. A drive waveform generator comprising:
 circuitry configured to: 
 generate a drive waveform; and 
 apply the drive waveform to a liquid discharge head to cause the liquid discharge head to discharge a liquid, 
 the drive waveform including: 
 a plurality of discharge pulses consisting of a first discharge pulse to cause the liquid discharge head to discharge the liquid and a second discharge pulse after the first discharge pulse to cause the liquid discharge head to discharge the liquid, the first discharge pulse and the second discharge pulse are in a nonresonant state; 
 a pulse interval between the first discharge pulse and the second discharge pulse, the pulse interval is set to a time period in which the liquid is discharged by the second discharge pulse in the nonresonant state in which the second discharge pulse is nonresonant with a meniscus vibration generated by the first discharge pulse; and 
 a non-discharge pulse between the first discharge pulse and the second discharge pulse, wherein the non-discharge pulse generates another meniscus vibration that does not cause the liquid discharge head to discharge the liquid. 
 
     
     
       13. The drive waveform generator according to  claim 12 ,
 wherein the drive waveform further includes: 
 another pulse interval between the non-discharge pulse and the second discharge pulse, said another pulse interval being equal to a time period in which the liquid is discharged by the second discharge pulse in a resonant state in which the second discharge pulse is resonant with the meniscus vibration generated by the non-discharge pulse. 
 
     
     
       14. A head drive method comprising:
 generating a drive waveform; and 
 applying the drive waveform to a liquid discharge head to cause the liquid discharge head to discharge a liquid, 
 the drive waveform including: 
 a plurality of discharge pulses consisting of a first discharge pulse to cause the liquid discharge head to discharge the liquid and a second discharge pulse after the first discharge pulse to cause the liquid discharge head to discharge the liquid, the first discharge pulse and the second discharge pulse are in a nonresonant state; 
 a pulse interval between the first discharge pulse and the second discharge pulse, the pulse interval is set to a time period in which the liquid is discharged by the second discharge pulse in the nonresonant state in which the second discharge pulse is nonresonant with a meniscus vibration generated by the first discharge pulse; and 
 a non-discharge pulse between the first discharge pulse and the second discharge pulse, wherein the non-discharge pulse generates another meniscus vibration that does not cause the liquid discharge head to discharge the liquid.